1. Field of the Invention
The invention relates to the use of certain 1,2,4-triazoles which are substituted in the 3 and 5 positions, and which may optionally be substituted in the 1 position as antigout and anti-hyperuricemic agents.
2. Description of the Prior Art
The herein-described 3,5-di-substituted-1,2,4-triazoles have utility as anti-gout and anti-hyperuricemic agents.
Gout is a condition affecting humans and lower animals, which is characterized by perversion of the purine metabolism resulting in hyperuricemia, i.e., an excess of uric acid in the blood, attacks of acute arthritis, and formation of chalky deposits in the cartilages of the joints. These deposits are made up chiefly of urates, or uric acid.
Uric acid serves no biochemical function in the body and is merely an end product of purine metabolism. It is well known in the art that the purine bases adenine and guanine, which play key roles in a wide variety of chemical processes, both give rise to uric acid in the body. Adenylic acid and guanylic acid are converted to the free purine bases by destructive metabolic enzymes. A portion of the free purine bases is converted to purine ribonucleotides and the remainder is degraded to the free bases xanthine and hypoxanthine. A single enzyme, xanthine oxidase, converts both xanthine and hypoxanthine to uric acid for excretion.
Although human purine biosynthesis can be inhibited at the stage of formyl glycinimide ribotide by the glutamine antagonists azaserine and 6-diazo-5-oxo-1-norleucine, a high incidence of undesirable side effects precludes their being used clinically for this purpose. In recent years, substantial progress has been made in attempting to control the excessive levels of uric acid in patients afflicted with gout through the use of pharmaceutical agents. Uric acid synthesis has been effectively blocked by the use of allopurinol, i.e., 4-hydroxypyrazolo-[3,4-d]-pyrimidine, a compound which is a structural isomer of hypoxanthine. Allopurinol acts as a specific inhibitor of the enzyme xanthine oxidase, which is responsible for the conversion of both hypoxathine and xanthine to uric acid. As a direct result of the administration of this compound to patients afflicted with gout, part of the uric acid which would normally end up in the urine is replaced by the oxypurines, hypoxanthine and xanthine, thus greatly reducing the content of uric acid in serum and urine. Azathioprine has also been used to inhibit excessive purine synthesis, and thus reduce the abnormally high amounts of uric acid found in the serum and urine of afflicted patients. Other compounds, such as acetylsalicyclic acid, thiophenylpyrazolidine and phenylbutazone have been employed in the treatment of gout. Many of the existing compounds used in the treatment of gout, however, relieve the inflammation and other symptoms connected therewith but have no effect on the conditions which give rise to gouty arthritis or hyperuricemia. Thus, there is still a need for compounds which can be employed in the prophylactic treatment of gout as well as for the treatment of other abnormal conditions associated with hyperuricemia.